[CI] [workflow] run browser tests directly, without using a virtual x…

… server environment

The browser tests, by default, do not require a graphical environment to run. Using one
might introduce problems.

Signed-off-by: Marc Dumais <marc.dumais@ericsson.com>

.github/workflows/ci-cd.yml

@@ -106,7 +106,7 @@ jobs:
       - name: Test (browser)
         if: matrix.tests != 'skip' && runner.os == 'Linux'
         run: |
-          xvfb-run -a yarn browser test
+          yarn browser test
 
       - name: Test (electron)
         if: matrix.tests != 'skip' && runner.os == 'Linux'